Chilton takes pole at Sonoma
Tom Chilton outshone team-mate and World Touring Car Championship runaway leader Yvan Muller at Sonoma.
Chilton, the older brother of British Formula One driver Max, out-qualified his more esteemed RML colleague for the first time in his career.
Chilton did so with some time to spare as he crossed in one minute 45.583 seconds - 0.125secs ahead of Muller - from his last lap in the 10-minute second qualifying session.
"That's a nice chunk (of time)," Chilton told Eurosport.
"Everyone who was watching qualifying saw me rise from P7 in my first run to P5 and then in that last run I got passed. I had to work for that. It was not easy."
Muller is set to be crowned WTCC champion for the fourth time in his career at the Sonoma raceway this weekend, but he was forced to concede to Chilton today.
"All weekend I've felt like I had the legs over Yvan which has never happened," Chilton said.
"To get it right in qualifying at every corner rarely happens. I just managed to get everything right and keep on the black stuff. My heart is pumping."
Tiago Monteiro claimed third place on the grid with Spaniard Pepe Oriola fourth.
British duo Alex MacDowell and James Nash were next quickest with defending drivers' champion Robert Huff eighth.
Denmark's Michel Nykjaer, second in the overall standings, was ninth on the grid with Gabriele Tarquini a place further back.